Ignition device for oil burners

Abstract

An oil burner ignition circuit using a relaxation oscillator is disclosed. The step-up transformer has a tertiary winding magnetically coupled to a primary winding. The tertiary winding and a diode controls the dissipation in the circuit, and the recovery of energy to a capacitor of the relaxation oscillator.

The embodiments of the invention in which an exclusive property or right is claimed are defined as follows: 
     
       1. An ignition device for oil burners, comprising: a capacitor adapted to be connected to a source of alternating current through a choke coil to allow for the storage of electrical energy in said capacitor; transformer means having a primary winding, a step-up secondary winding, and a tertiary winding with the same magnetic polarity as said primary winding and which is magnetically coupled to said primary winding; said tertiary winding being coupled to said primary winding so that an electromotive force mutually induced in said tertiary winding is higher than and counter balanced with an electromotive force induced in said primary winding; a silicon controlled rectifier connected to said capacitor and in series circuit with said primary winding to control the discharge of said stored energy through said primary winding to induce a high voltage in said secondary winding which is in turn adapted to produce oil ignition sparks across a pair of electrodes; said silicon controlled rectifier including gate means to periodically gate said silicon controlled rectifier into conduction; and said tertiary winding being connected through a commutating diode to said capacitor with an output from said tertiary winding being supplied to said silicon controlled rectifier and said primary winding. 
     
     
       2. An ignition device for oil burners as described in claim 1 wherein said gate means includes a capacitor to store a gating potential for said silicon controlled rectifier. 
     
     
       3. An ignition device for oil burners as described in claim 2 further comprising a diode in series circuit with said choke coil between said source and said first capacitor to cause said first capacitor to store energy on only one half cycle of said alternating current source.